A STUDY OF 9 HIGH-REDSHIFT CLUSTERS OF GALAXIES - I - THE SURVEY

We present a description of the observations and data reduction proced ures for an extensive spectroscopic and multiband photometric study of nine high-redshift, optically selected cluster candidates. The primar y goal of the survey is to establish new constraints on cluster and ga laxy evolution, with specific emphasis on the evolution of galaxy morp hology and on the star formation history of the galaxies within and ar ound distant clusters. We have measured 892 new redshifts for galaxies with R less than or equal to 23.3. The data will also serve as deep p robes of the foreground and background large-scale structures. The obs ervations include broadband optical imaging and spectroscopy with the Low Resolution Imaging Spectrograph at the 10 m W. M. Keek Observatory telescope; K-band imaging with the IRIM camera at the 4 m Kitt Peak N ational Observatory telescope; and deep, high angular resolution imagi ng with the Wide Field Planetary Camera 2 on board the Hubble Space Te lescope. We also describe the procedures used to obtain morphological information. We have established that six of the nine cluster candidat es are indeed real space density enhancements and are representative o f those typically associated with clusters of galaxies. The remaining three candidates appear to be projections of several smaller groups at widely separated distances. This success rate is consistent with esti mates of the false-positive rate in two-dimensional optical high-z clu ster searches.